Error

while clicking on checkbox below error is thrown .How to resolve this issue

Could not display interface. Please check definition and inputs. Interface Definition: Expression evaluation error [evaluation ID = YNISEST2] : An error occurred while executing a save: Expression evaluation error: The save target must be a load() variable, process variable, or node input (or a rule input passed one of those three), but instead was: [selected=, pagingInfo=[startIndex=1, batchSize=-1, sort=[field=property_name, ascending=true]]]

I am attaching code below

= load(
  /*local!gridSelection: a!gridSelection(
    selected: local!existingUserPropertyIds,
    pagingInfo: a!pagingInfo(
      startIndex: 1,
      batchSize: - 1,
      sort: a!sortInfo(
        field: "property_name",
        ascending: true
      )
    )
  ),
  local!properties: a!queryEntity(
    entity: cons!OR_PROPERTY_INFO,
    query: a!query(
      pagingInfo: local!gridSelection.pagingInfo
    ),
    fetchTotalCount: true
  ),*/
  a!sectionLayout(
    contents: {
      with(
        local!userDetails: if(
          isnull(
            ri!userId
          ),
          null,
          a!queryEntity(
            entity: cons!OR_USER,
            query: a!query(
              filter: a!queryFilter(
                field: "user_id",
                operator: "=",
                value: ri!userId
              ),
              pagingInfo: a!pagingInfo(
                startIndex: 1,
                batchSize: - 1
              )
            )
          ).data
        ),
        a!boxLayout(
          label: "ADD NEW USER",
          contents: {
            a!columnsLayout(
              columns: {
                a!columnLayout(
                  contents: {
                    a!textField(
                      label: "First Name",
                      labelPosition: "ABOVE",
                      placeholder: "First name",
                      value: if(
                        isnull(
                          local!userDetails
                        ),
                        ri!userDetails.first_name,
                        local!userDetails.first_name
                      ),
                      saveInto: ri!userDetails.first_name,
                      refreshAfter: "UNFOCUS",
                      required: true,
                      requiredmessage: "Please enter first name",
                      validations: {}
                    )
                  }
                ),
                a!columnLayout(
                  contents: {
                    a!textField(
                      label: "Last Name",
                      labelPosition: "ABOVE",
                      placeholder: "Last name",
                      value: if(
                        isnull(
                          local!userDetails
                        ),
                        ri!userDetails.last_name,
                        local!userDetails.last_name
                      ),
                      saveInto: ri!userDetails.last_name,
                      refreshAfter: "UNFOCUS",
                      required: true,
                      requiredmessage: "Please enter last name",
                      validations: {}
                    )
                  }
                )
              }
            ),
            a!columnsLayout(
              columns: {
                a!columnLayout(
                  contents: {
                    a!textField(
                      label: "Email",
                      labelPosition: "ABOVE",
                      placeholder: "Email",
                      value: if(
                        isnull(
                          local!userDetails
                        ),
                        ri!userDetails.primary_email,
                        local!userDetails.primary_email
                      ),
                      saveInto: ri!userDetails.primary_email,
                      refreshAfter: "UNFOCUS",
                      required: true,
                      requiredmessage: "Please enter email",
                      validations: {}
                    )
                  }
                ),
                a!columnLayout(
                  contents: {
                    a!dropdownField(
                      label: "Role",
                      labelPosition: "ABOVE",
                      placeholderLabel: "--- Select a Role ---",
                      choiceLabels: {
                        "Owner",
                        "Manager",
                        "Resident"
                      },
                      choiceValues: {
                        cons!OWNER_ROLE_ID,
                        cons!MANAGER_ROLE_ID,
                        cons!RESIDENT_ROLE_ID
                      },
                      value: if(
                        isnull(
                          local!userDetails
                        ),
                        ri!userDetails.role_id,
                        local!userDetails.role_id
                      ),
                      saveInto: ri!userDetails.role_id,
                      required: true,
                      requiredmessage: "Please select role",
                      validations: {}
                    )
                  }
                )
              }
            )
          },
          style: "STANDARD",
          marginBelow: "STANDARD"
        )
      ),
      a!columnsLayout(
        columns: {
          a!columnLayout(
            contents: {
              a!richTextDisplayField(
                label: "",
                labelPosition: "COLLAPSED",
                value: {
                  a!richTextHeader(
                    text: "Select Properties"
                  )
                }
              ),
              with(
                
                local!existingUserPropertyMappingInfo: if(
                  isnull(
                    ri!userId
                  ),
                  {},
                  a!queryEntity(
                    entity: cons!OR_USER_PROPERTY_INFO,
                    query: a!query(
                      filter: a!queryFilter(
                        field: "user_id",
                        operator: "=",
                        value: ri!userId
                      ),
                      pagingInfo: a!pagingInfo(
                        startIndex: 1,
                        batchSize: - 1
                      )
                    )
                  ).data
                ),
                local!existingUserPropertyIds: {
                  a!forEach(
                    items: local!existingUserPropertyMappingInfo,
                    expression: fv!item.property_id
                  )
                },
                local!gridSelection: a!gridSelection(
                  selected: local!existingUserPropertyIds,
                  pagingInfo: a!pagingInfo(
                    startIndex: 1,
                    batchSize: - 1,
                    sort: a!sortInfo(
                      field: "property_name",
                      ascending: true
                    )
                  )
                ),
                local!properties: a!queryEntity(
                  entity: cons!OR_PROPERTY_INFO,
                  query: a!query(
                    pagingInfo: a!pagingInfo(
                      startIndex: 1,
                      batchSize: - 1,
                      sort: a!sortInfo(
                        field: "property_name",
                        ascending: true
                      )
                    )
                  ),
                  fetchTotalCount: true
                ),
                
                a!gridField(
                  label: "Select Properties",
                  labelPosition: "COLLAPSED",
                  totalCount: local!properties.totalCount,
                  columns: {
                    a!gridTextColumn(
                      label: "Property Name",
                      field: "property_name",
                      data: index(
                        local!properties.data,
                        "property_name",
                        {}
                      )
                    ),
                    a!gridTextColumn(
                      label: "Address",
                      field: "address_line1",
                      data: index(
                        local!properties.data,
                        "address_line1",
                        {}
                      )
                    )
                  },
                  identifiers: local!properties.identifiers,
                  value: local!gridSelection,
                  saveInto: {
                    local!gridSelection,
                    a!save(
                      ri!userPropertyInfo,
                      a!forEach(
                        items: local!gridSelection.selected,
                        expression: {
                          property_id: fv!item,
                          is_active: 1,
                          user_property_status: 1
                        }
                      )
                    )
                  },
                  selection: true,
                  selectionStyle: "CHECKBOX",
                  shadeAlternateRows: true,
                  rowHeader: 1
                )
              ),
              /*a!textField(
                label: "Selected Property IDs",
                value: if(
                  length(
                    local!gridSelection.selected
                  ) = 0,
                  "No Property selected",
                  joinarray(
                    local!gridSelection.selected,
                    ", "
                  )
                ),
                readOnly: true
              )*/
              
            }
          )
        }
      ),
      a!columnsLayout(
        columns: {
          a!columnLayout(
            contents: {
              a!buttonArrayLayout(
                buttons: {
                  a!buttonWidget(
                    label: "Cancel",
                    style: "NORMAL",
                    saveInto: {
                      a!save(
                        target: ri!actionEvent,
                        value: "listUsers"
                      ),
                      a!save(
                        target: ri!userId,
                        value: null
                      )
                    }
                  ),
                  a!buttonWidget(
                    label: "Save",
                    submit: true,
                    style: "PRIMARY",
                    disabled: false
                  )
                },
                align: "END"
              )
            }
          )
        }
      )
    }
  )
)